x4PayAPI Market

Identify which carrier issued a tracking number using a deterministic,…

Identify which carrier issued a tracking number using a deterministic, versioned signature set - prefixes, lengths, carrier check digits and UPU S10 structure - returning the carrier, how distinctive the match is, every ranked candidate with typed evidence, and the parsed S10 details. Identify which carrier issued a tracking number using a deterministic, versioned signature set - prefixes, lengths, carrier check digits and UPU S10 structure - returning the carrier, how distinctive the match is, every ranked candidate with typed evidence, and the parsed S10 details. No upstream call and no carrier account required. Use when: Which carrier is this tracking number from?

1 route settlement-verified · $0.001 USDC/request · 1 endpoint · Verification · base network · x402 protocol

Verified routes

Other routes are unverified.

Networks: Base (settlement-verified)

Discovery is free. Agents search the catalogue here. Payment happens on the listing 402, not on PayAPI.

url https://payapi.market/mcp

About this API

Identify which carrier issued a tracking number using a deterministic,… is listed in the Verification category with pricing at $0.001 USDC/request. One route has been settlement-verified by PayAPI Market on 2026-10-21. View receipt on Basescan.

Payments settle on base in USDC via the x402 protocol. AI agents discover this API through the PayAPI Market MCP server and pay per request without API keys or accounts.

This API exposes 1 endpoint.

How to call this API

Every protected route returns HTTP 402 with x402 payment requirements. An agent pays the stated USDC amount on Base and retries with the payment header. No API keys, no accounts. Browse the marketplace or list your own API.

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